docs: def latex_repr(self):
          """A LaTeX representation for the unit
  
          Examples
          --------
          >>> from unyt import g, cm
          >>> (g/cm**3).units.latex_repr
          '\\\\frac{\\\\rm{g}}{\\\\rm{cm}^{3}}'
          """
          if self._latex_repr is not None:
              return self._latex_repr
          if self.expr.is_Atom:
              expr = self.expr
          else:
              expr = self.expr.copy()
          self._latex_repr = _get_latex_representation(expr, self.registry)
          return self._latex_repr